import datetime


class Subject:
    def __init__(self,
                 subjectID: int = None,
                 time: datetime = None,
                 content: str = None,
                 userID: str = None):
        self.subject_ID = subjectID
        self.time = time
        self.content = content
        self.userID = userID

    def to_string(self):
        return "subjectID: {}, time: {}, content: {}, userID: {}".format(
            self.subject_ID, self.time, self.content, self.userID)
